The invention relates to a dispenser suitable for discharging or storing particulate media, a flowable medium. Each of these media may be liquid, pasty, powdery and/or gaseous.
In medical hypodermic syringes or the like, the dispenser comprises a barrel including a piston and an injection needle serving both as an inlet and outlet for the medium. In contrast thereto, in the invention the passages are separate or spaced away from each other, e.g. at ends of a body facing away from each other, through which the medium flows and which may be a valve or pump body. This body may comprise three, four or more inner widths each differing from the other and offset from each other and house at least two, three or more components internally. In addition, the body comprises means, such as a flange for connecting a base which may be solely a medium reservoir or comprise a medium reservoir.
The invention is based on the object of providing a dispenser which avoids the disadvantages of known configurations and the cited hypodermic syringes. More particularly it is intended that at least one of the medium passages is suitable for piercing diaphragms, tissue or the like. Furthermore, closures or walls are intended to be opened by the dispenser by simple ways and means. Handling of the dispenser is simplified.
In accordance with the invention, the body comprises a freely protruding piercing or opening member, such as a hollow or pointed piercing needle, which is made of a material whose properties correspond to those of steel or hardened steel. The piercing member may have an outer width of less than 2 mm or a wall thickness which is greater than half or two-thirds of the inner width. When the piercing member is used as the outlet, the dispenser can be used as a syringe. When used as an inlet the dispenser can be sealingly connected by the piercing action to a medication cartridge, such as a carpule. Although the piercing member could be mounted to be movable on the body in overcoming a spring force, it is however expediently and non-releasably connected thereto, e.g. by the injection molding action when the body is molded in a plastics material. All parts of the dispenser with the exception of one or more springs may be injection molded or formed of plastics parts. The dispenser is designed for holding and simultaneous actuation of all of its functions with one hand.
The body is advantageously provided with communicating paths for the medium, at least one of which is variable in its length or cross-section. For this purpose a piston, a valve or some other control element may be provided in the body. Preferably the dispenser comprises a pump, such as a plunger pump comprising one or more manually actuatable valves or one or more pressure relief valves.
It is particularly advantageous when the body and a medium reservoir forms a preassembly so that in the starting position the piercing member has yet to open the reservoir, it not being until manually actuated that the reservoir is first opened and subsequently the medium exchanged between the reservoir and the body due to both then intercommunicating.
The outlet may be configured for dispensing droplets, a jet of the medium, or as an atomizing nozzle. Preferably the outlet is provided in a nozzle suitable for insertion into a body opening of a patient.
The body or the element provided for penetration of the piercing member may be shielded outwardly partly, mostly or totally so that protection from damage is assured. Each piston of the dispenser may be a valve and/or a displacement element.
The dispenser advantageously comprises two finger rests located transversely to the direction of the stroke and spaced away from each other. The finger rests approach each other on actuation and are suitable for both the piercing stroke and a pumping stroke or for a filling stroke by which the medium in the reservoir is communicated into the region of the medium inlet. Each of these strokes may be counteracted by a restraint at the start of the stroke which can be defeated by a sudden increased actuating force, after which the forces counteracting the further actuatation are instantaneously many times less than the restraining forces to thus permit high flow rates of the medium or a high impingement velocity of the piercing member on piercing.
Piercing may require overcoming a spring force independently of the piercing cross-section to thus preserve the piercing member and the piercing cross-section due to piercing being attentuated by the spring force and is also powered when the spring force is sufficiently high. Advantageously, however, the spring is rigidly supported and is only the element to be pierced is elastic.
Reference is made to the German patents pending 196 10 457, 197 39 990 and 196 37 101 for further description of the operational effects of a dispenser made according to the present invention.
These and further features read not only from the claims but also from the description and the drawings. Each of the individual features is achieved by itself or severally in the form of sub-combinations in one embodiment of the invention and in other fields and may represent advantageous aspects as well as being patentable in its own right, for which protection is sought in the present. The division of the application into sections including sub-titling does not restrict the general validity of the comments made thereunder.